Accurate design of trimmingless high-temperature superconducting filters

Complex approach to the design of microstrip resonators and filters based on High Temperature Superconductor (HTS) films is described, which includes modeling of the electrodynamics parameters of HTS films, design of microstrip resonators and filters, their manufacturing, and testing. Test samples of resonators were prepared using YBCO films on LaAlO₃ and r-cut sapphire substrates. The resonator and filter structures were patterned using ion beam lithography. Experimental data were used for extracting parameters of the model of the YBCO film surface impedance. Using the correct model parameters, the following filters have been designed and tested: 4th order band-pass filter, 14-pole band-pass filter, two band-reject filters for applications in microwave frequency range, and 5-pole mm-wave filter for radio-astronomy receiving module.